One of the pins from the expansion slot carries signals to drive daisy chained WS2812B RGB LEDs (Certain Neopixels from Adafruit use this model ). Each RGB LED supports 24-bit color(16-million shades) and they can be addressed using a simple python command that accepts a 2D array containing color info for each LED.

A demo app was written using the ColorPicker button that's part of the PyQtGraph toolkit that's used extensively with the vLabtool. The button launches a QColorPicker Widget for each LED in the chain, and the colors are set using